This invention relates to the use of adhesive systems comprising a fluorescent dye for various bonding applications in an intraluminal medical device, in particular the catheter assembly or stent delivery system. The fluorescent adhesive allows for easy and non-destructive inspection of the bond quality, as well as allowing easy determination of imperfections or tears in the balloon material.
Adhesives are used for a variety of applications in the manufacture of catheter assemblies. One such application involves mounting a balloon on a catheter assembly. Balloon catheters may be used to widen a vessel into which the catheter is inserted by dilating the blocked vessel, such as in an angioplasty procedure. Balloon catheters may also be used to expand and/or seat a medical device such as a stent or graft at a desired position within a body lumen. In all of these applications, fluid under pressure is supplied to the balloon through an inflation lumen in the catheter, thereby expanding the balloon.
The bonding of a catheter balloon to a catheter in particular requires that the adhesive form an excellent seal between the balloon and the catheter. This is due to the fact that once properly positioned within a patient""s body vessel, the balloon is inflated by filling it with inflation fluid under high pressure which the adhesive seal must be able to withstand. An improper or poor seal may result in leakage of inflation fluid into the patient, inability to achieve the proper inflation pressure, and even deflation of the balloon due to pressure loss thus requiring that the procedure be repeated.
A number of methods for sealing a balloon to a catheter are currently known in the art. U.S. Pat. No. 4,913,701 to Tower describes a method of bonding a polyurethane balloon to a polyethylene catheter using a cyanoacrylate adhesive. U.S. Pat. No. 4943278 to Euteneuer, et al. also describes a method of mounting a balloon member to a catheter by bonding, such as by an epoxy. U.S. Pat. No. 4661095 to Taller et al. describes bonding polyurethane balloons to catheters formed of thermoplastic polyurethane using special polyurethane adhesives.
There are numerous other applications in the manufacture of catheter assemblies where adhesives and/or fusion methods are used to adhere parts of the catheter together. For instance, catheters are often constructed of two or more segments requiring a bonding and/or fusion method for sealing the segments together. For instance, catheter may be constructed of two or more shafts such as an outer shaft and an inner shaft, where the two shafts are then bonded together.
Other applications where adhesives might be used include bonding the manifold to the catheter shaft at the proximal end of the catheter, bonding of the guide wire port to the catheter shaft, for bonding a soft tip to the distal end of a catheter shaft, for bonding socs, for bonding marker bands, for bonding hypotubes to a polymeric tube, and so forth.
There remains a need in the art to be able to ascertain whether or not the adhesive has been accurately and properly applied to the medical device and at a precise location on the device, and whether or not a quality seal has been formed, especially in the case of bonding a catheter balloon to a catheter.
The present invention relates to the use of fluorescent dyes in adhesives used for various bonding applications in intraluminal medical devices, in particular, catheter assemblies. The fluorescent dyes allow the adhesive bond to be easily inspected for the bond quality without destruction of the bond and/or substrates.
Use of these fluorescing agents makes it easy to see exactly where the adhesive is being applied and to improve the accuracy of the application, particularly where operators are inexperienced. Because the adhesives used on these medical devices are typically clear and colorless or substantially so, are typically applied by hand, and the devices are typically quite small, it can be very difficult to accurately apply adhesive at the desired location on the device. The addition of a fluorescing agent, however, makes the bond visible under UV light thus allowing easy inspection of the bond.
More particularly, the present invention relates to an intraluminal medical device comprising at least two substrates or components of the same or a different material wherein the at least two substrates are bonded together with an adhesive comprising a fluorescing agent which fluoresces at a wavelength between about 200 nm and about 800 nm. The fluorescing agent is preferably a derivative of benzoxazole, a derivative of pyrene, a derivative of naphthalene, or some mixture thereof.
Even more particularly, the present invention relates to an intraluminal medical device comprising an elongated tubular member having a proximal end and a distal end and an inflatable balloon member located at the distal end of the tubular member and extending distally therefrom. The balloon member also has a proximal end and a distal end, and is made of a flexible material. The elongated tubular member and the inflatable balloon member are bonded together with an adhesive comprising a fluorescing agent resulting in an adhesive that fluoresces upon exposure to an ultra-violet light source.
The present invention further relates to stent delivery system comprising a stent delivery catheter and at least one stent retaining sleeve, the stent retaining sleeve being fixedly attached to the stent delivery catheter with an adhesive comprising at least one fluorescing agent. The adhesive fluoresces when exposed to ultraviolet radiation.
The present invention further relates to a method of detecting an adhesive bond in an intraluminal medical device having multiple substrates of the same or different materials, comprising the steps of adding a fluorescing agent to an adhesive composition, applying the adhesive composition to an intraluminal medical device where the adhesive composition forms an adhesive bond between substrates on the intraluminal medical device, irradiating the adhesive with a source of energy capable of inducing the emission of ultraviolet radiation having a wavelength of about 200 nm to about 800 nm, and observing the emitted ultraviolet radiation to determine the presence and location of said adhesive.
The fluorescing agent may be a benzoxazole derivative, a naphthalene derivative, a pyrene derivative, or some mixture thereof.